高糖高脂联合低剂量链脲佐菌素对版纳微型猪骨骼肌糖原合成及肌肉素表达的影响

Effect of high sucrose/high fat diet and Streptozotocin on amylon composition and musclin expression of skeletal muscles in Chinese Banna mini pigs

目的观察高糖高脂联合低剂量STZ对版纳微型猪骨骼肌肌肉素(Musclin)表达的影响。方法高糖高脂联合低剂量STZ诱导版纳微型猪T2DM模型,每月末测定血糖、血脂、胰岛素及Musclin水平变化。12个月末处死动物,HE和PAS及骨骼肌糖原含量(M2酶标仪,比色法)测定,ELISA检测血清Musclin含量,Western blot检测肌肉Musclin蛋白表达。结果喂养12月后,与对照(Con)组比较,模型(HSFD)组血糖[(4.75±0.2)vs(19.28±2.24)mmol/L]、TG[(0.82±0.14)vs(2.46±0.29)mmol/L]和TC[(2.29±0.35)vs(8.93±0.43)mmol/L]升高(P<0.05),胰岛素缺乏[(8.25±1.04)vs(3.81±0.39)mU/L,P<0.05];骨骼肌萎缩,糖原合成减少[(0.42±0.05)vs(0.29±0.04)μg/ml,P<0.05];血清Musclin达峰值[(249.56±19.14)vs(409.43±21.34)pg/ml,P<0.05],骨骼肌组织Musclin蛋白表达升高21%(P<0.05)。结论高糖高脂联合STZ可诱导版纳微型猪发生IR、糖尿病,促进骨骼肌萎缩,抑制糖原合成,可能与信号分子Musclin激活有关。

Objective To investigate the effect of high-fat/high-sucrose/streptozotocin（STZ）on musclin levels in the skeletal muscles of Chinese Banna mini pigs. Methods T2DM model of Chinese Banna mini pigs were induced by feeding with high-fat/high-sucrose and treating with Streptozotocin（HSFD group）.Plasma glucose,lipids,insulin,and musclin were measured at the end of each month.After following up for 12 months,all the Banna mini pigs were killed.Skeletal muscles were observed by HE staining,periodic acid Schiff reaction（PAS）staining.The glycogen content（Colorimetry,SpectraMax M2）was determined.The level of serum musclin was measured by ELISA,and the expression of musclin protein was tested by Western blot. Results After 12 months＇ follow up,plasma glucose[（19.28±2.24）vs（4.75±0.2）mmol/L],triacylglyceride[（2.46±0.29）vs（0.82±0.14）mmol/L],and total cholesterol[（8.93±0.43）vs（2.29±0.35）mmol/L]were markedly increased in HSFD group than in Con group（P〈0.05）.Insulin[（3.81±0.39）vs（8.25±1.04）mU/L]and glycogen level[（0.29±0.04）vs（0.42±0.05）μg/ml]were significantly decreased in HSFD group than in Con group（P 0.05）.Compared with Con group,skeletal muscle fiber atrophy could be seen in HSFD group.The peak of serum Musclin[（409.43±21.34）vs（249.56±19.14）pg/ml]was significantly higher in HSFD group than in Con group（P〈0.05）.And the expression of musclin protein increased 21%in HSFD group than in Con group（P〈0.05）. Conclusion In Banna mini pigs,high sucrose/high fat diet and STZ could induced IR and diabetes mellitus,promoteskeletal muscle fiber atrophy,and inhibit glycogen synthesis,which may be related to musclin activation.